Then despite the most likely annoying bugs with BF2's lock system, we should go with heat seeking. And also TV guided mode, but without the camera on the missile. Use up the weapon slots for the gunner!

Heat seeking and laser guided are technically the same system. They work the same and thus have the same bugs. The only difference between heat seeking and laser guided is the target object they seek.

In PR they just removed the laser target object and put it in a projectile that is fired out of the SOFLAM (GLTD). They kept the thermal (heat) target object on aircraft though. The tracking and seeking systems for heat seeking and laser guided weapons are exactly the same thus they suffer from the same problem. The only difference between those two systems is the object they seek. You can put a thermal object on any other object on the game just as you can put a laser object on any object in the game. You can put both target objects on anything else in the game at the same time.

Rather than thinking of them as two different missile systems as they are presented in game, think of them as "a guided missile" where the coder can specify if the missile seeks heat or the missile seeks a laser.